Infections having fungal origins constitute a large portion of human diseases caused by microorganisms. Several naturally occurring antibiotics and numerous synthetic compounds are currently available for treating fungal infections. Nystatin, a polyene antibiotic whose structural formula is not yet fully elucidated, is a commonly used antifungal agent which has met with good success. Even with the currently available antifungal agents however, there are still several diseases of fungal origin which are not easily controllable. Additionally, certain antifungal agents become ineffective with continued use due to the patient's sensitization to the particular drug. Consequently, the search for new antifungal agents and the therapy of fungal infections is the object of much laboratory and clinical investigation.
The isolation and characterization of novel 24-methylene-14a-aza-D-homo-cholestadines which show good antifungal activity has recently been accomplished from cultures of a strain of Geotrichum flavo-brunneum. This organism is described in detail by Miller et al., Mycologia 49, 779-808, 1957. The preparation and isolation of these noval azasteroids is the subject of U.S. Pat. No. 3,845,203.
The compounds provided by the present invention are in general prepared by modifying the side chain portion of the above-mentioned naturally occurring 24-methylene-14a-aza-D-homo-cholestadines. The compounds provided herein are useful as antifungal agents.